This invention relates to systems for open-end spinning, and particularly to systems for aero-mechanical open-end spinning.
The technique for open-end spinning is process of separating staple fibers from an input feedbunch and transporting them to a revolving open-end reassembly and twisting point to form a yarn. There are at least three main approaches to open-end spinning: aero-dynamic systems, electro-mechanical systems, and aero-mechanical systems.
In aero-dynamic systems, a spiral airflow is produced downwardly in a tube into which separated staple fibers are introduced by means of a secondary air inlet. A seed yarn is introduced into the spiral flow, and the separated fibers gather on its tail. The seed yarn is withdrawn from the tube and, as it is withdrawn, the staple fibers gathered on it are twisted by the rotation of the yarn in the airstream. The yarns produced by this method are, however, weak and irregular.
In electro-mechanical systems, electrostatic forces generated from high potentials (on the order of 30 kilovolts) transport the separated staple fibers from a drafting system, and hold them in control during the mechanical twisting action imparted by a rotating needle basket.
In aero-mechanical systems, the separated staple fibers are delivered along with the air stream into a revolving rotor (often referred to as a spinning rotor or turbine), forming a fiber ring around the periphery thereof. A seed yarn is introduced into the rotor, and its tail collects the fibers lying around the periphery. The fibers so collected are twisted into the yarn by the rotation of the rotor as the seed yarn is withdrawn. This is a system of open-end spinning which has been commercially exploited. Machines employing this system including that manufactured by Toyoda Automatic Loom Works, Ltd. of Aichi-ken, Japan, known as Model BS, and that manufactured by Schurr, Stahlecker and Grill GmbH, Suessen, West Germany, known as the Suessen Open-End Spintester. Such open end spinning machines have been described in detail in numerous publications and patents.
Despite its commercialization, the yarn produced by present aero-mechanical systems does not possess the strength or quality of yarn produced by the more conventional ring spinning systems.
In aero-mechanical systems, an important factor in producing yarn comparable in strength with ring spun yarns is the parallelism of the separated staple fibers which form the fiber ring around the periphery of the revolving rotor. As is known in the prior art, the separation of staple fibers in the aero-mechanical systems presently in use is effected by a toothed combing roller. In such systems it would be beneficial to the production of high quality yarn if the separated staple fibers could be paralleled as they leave the combing roller and enter the airstream to be deposited on the periphery of the revolving rotor in a more parallel condition.